Buggy code:
public abstract class AssistParser extends Parser { public AstNode assistNode ; public boolean isOrphanCompletionNode ; int [ ] blockStarts = new int [ 30 ] ; protected int previousToken ; protected int previousIdentifierPtr ; protected int invocationPtr ; protected int [ ] selectorStack = new int [ Parser . StackIncrement ] ; protected static final int THIS_CONSTRUCTOR = - 1 ; protected static final int SUPER_CONSTRUCTOR = - 2 ; protected int inInitializerPtr ; protected boolean [ ] inInitializerStack = new boolean [ Parser . StackIncrement ] ; protected int inMethodPtr ; protected boolean [ ] inMethodStack = new boolean [ Parser . StackIncrement ] ; public AssistParser ( ProblemReporter problemReporter , boolean assertMode ) { } public abstract char [ ] assistIdentifier ( ) { } public int bodyEnd ( AbstractMethodDeclaration method ) { } public int bodyEnd ( Initializer initializer ) { } public RecoveredElement buildInitialRecoveryState ( ) { } protected void consumeClassBodyDeclarationsopt ( ) { } protected void consumeClassBodyopt ( ) { } protected void consumeClassHeader ( ) { } protected void consumeConstructorBody ( ) { } protected void consumeConstructorHeader ( ) { } protected void consumeEmptyClassBodyDeclarationsopt ( ) { } protected void consumeEnterAnonymousClassBody ( ) { } protected void consumeExplicitConstructorInvocation ( int flag , int recFlag ) { } protected void consumeForceNoDiet ( ) { } protected void consumeInterfaceHeader ( ) { } protected void consumeInterfaceMemberDeclarationsopt ( ) { } protected void consumeMethodBody ( ) { } protected void consumeMethodHeader ( ) { } protected void consumeMethodInvocationName ( ) { } protected void consumeMethodInvocationPrimary ( ) { } protected void consumeMethodInvocationSuper ( ) { } protected void consumeNestedMethod ( ) { } protected void consumeOpenBlock ( ) { } protected void consumePackageDeclarationName ( ) { } protected void consumeRestoreDiet ( ) { } protected void consumeSingleTypeImportDeclarationName ( ) { } protected void consumeStaticInitializer ( ) { } protected void consumeStaticOnly ( ) { } protected void consumeToken ( int token ) { } protected void consumeTypeImportOnDemandDeclarationName ( ) { } public abstract ImportReference createAssistImportReference ( char [ ] [ ] tokens , long [ ] positions ) { } public abstract ImportReference createAssistPackageReference ( char [ ] [ ] tokens , long [ ] positions ) { } public abstract NameReference createQualifiedAssistNameReference ( char [ ] [ ] previousIdentifiers , char [ ] name , long [ ] positions ) { } public abstract TypeReference createQualifiedAssistTypeReference ( char [ ] [ ] previousIdentifiers , char [ ] name , long [ ] positions ) { } public abstract NameReference createSingleAssistNameReference ( char [ ] name , long position ) { } public abstract TypeReference createSingleAssistTypeReference ( char [ ] name , long position ) { } public void flushAssistState ( ) { } protected TypeReference getTypeReference ( int dim ) { } protected NameReference getUnspecifiedReferenceOptimized ( ) { int completionIndex ; if ( ( completionIndex = indexOfAssistIdentifier ( ) ) < 0 ) { return super . getUnspecifiedReferenceOptimized ( ) ; } int length = identifierLengthStack [ identifierLengthPtr ] ; char [ ] [ ] subset = identifierSubSet ( completionIndex ) ; ( identifierLengthPtr ) -- ; identifierPtr -= length ; long [ ] positions = new long [ length ] ; System . arraycopy ( identifierPositionStack , ( ( identifierPtr ) + 1 ) , positions , 0 , length ) ; NameReference reference ; if ( completionIndex == 0 ) { reference = this . createSingleAssistNameReference ( assistIdentifier ( ) , positions [ 0 ] ) ; } else { reference = this . createQualifiedAssistNameReference ( subset , assistIdentifier ( ) , positions ) ; } <START_BUG> reference . bits &= ~ ( NameReference . RestrictiveFlagMASK ) ; <END_BUG> reference . bits |= ( LOCAL ) | ( FIELD ) ; assistNode = reference ; lastCheckPoint = ( reference . sourceEnd ) + 1 ; return reference ; } public void goForBlockStatementsopt ( ) { } public void goForConstructorBlockStatementsopt ( ) { } protected char [ ] [ ] identifierSubSet ( int subsetLength ) { } protected int indexOfAssistIdentifier ( ) { } public void initialize ( ) { } public abstract void initializeScanner ( ) { } public void parseBlockStatements ( AbstractMethodDeclaration md , CompilationUnitDeclaration unit ) { } public void parseBlockStatements ( ConstructorDeclaration cd , CompilationUnitDeclaration unit ) { } public void parseBlockStatements ( Initializer ini , TypeDeclaration type , CompilationUnitDeclaration unit ) { } public void parseBlockStatements ( MethodDeclaration md , CompilationUnitDeclaration unit ) { } protected void prepareForBlockStatements ( ) { } protected void pushNotInInitializer ( ) { } protected void pushNotInMethod ( ) { } protected void pushOnSelectorStack ( int selectorIdPtr ) { } public void reset ( ) { } protected void resetStacks ( ) { } protected boolean resumeAfterRecovery ( ) { } public abstract void setAssistIdentifier ( char [ ] assistIdent ) { } protected AstNode wrapWithExplicitConstructorCallIfNeeded ( AstNode ast ) { } }

Fix:
reference . bits &= ~ ( AstNode . RestrictiveFlagMASK ) ;